β-Sheet Replication

 

Selective replication of amphiphilic prebiotic peptides. Non enzymatic peptide replication, as well as replication of other types of molecules, has been the subject of intense research over the past two decades. Several research groups, including our group, have used rather long replicating entities, a-helix forming, peptide sequences that self-assemble to coiled coils tertiary structures. However, it has been postulated that shorter peptides with simpler sequences may also serve as templates for self-replication, provided that they are able to arrange themselves into unique and well defined structures. We study simple amphiphilic peptides, close analogs of the synthetic Glu-(Phe-Glu)n peptides, that form soluble one-dimensional b-sheet (fibril) aggregates in water and can serve to signi​ficantly accelerate ligation and their own self replication. We have described the design, synthesis, self-assembly and replication kinetics of this novel system, and also discussed its relevancy to different plausible scenarios in early molecular evolution and the origins of life.